Question

помогите
1) (t² + 8t - 9) - (t² - 11t + 10) = 18t - 20 (уравнение)
2) -0.8c(c + 5) - 0.7(10c+5) + 0.8c² + 10c - 4 =
3) 3x(x - 2) - (3x - 1)(x + 4) ≥ 8(2 -x) (уравнение)
4) (2m⁵n⁴)⁷ * (4m³n⁵)² / (2m⁴n⁴)¹° =

Answer 1

1) ($( t^{2} + 8*t - 9) - ( t^{2} -11 * t +10) = 18 * t - 20$
19 * t - 19 = 18 * t - 20
t = -1

2)$-0,8c^{2} (c+5) - 0,7(10c+5) + 0,8 c^{2} + 10c - 4 =$
$= -0,8 c^{2} -4c - 7c - 3,5 + 0,8 c^{2} +10c -4 =$
$= -c - 7,5$

3)3x(x-2)-(3x-1)(x+4) ≥ 8(2-x)
$3 x^{2} -6x-3 x^{2} +x-12x+4 geq 16-8x$
-9x ≥ 12
x ≥ 12/(-9)

4)$( 2m^{5} n^{4} ) ^{7} * (4 m^{3} n^{5} ) ^{2} / (2 m^{4} n^4) ^{10} }$ = 
= $(2 m^{5} n^{4}) ^{7} * (4m^{3} n^{5} ) ^{2} / ((2 m^{4} n^{4}) ^{7} * (2 m^{4} n^{4}) ^{3})$=
=$( m^{7} * (4 m^{3} n^{5} ) ^{2} )/(2 m^{4} n^{4} ) ^{3}$= 
=$m^{7} * 2^{4} * ( m^{3} n^{5} ) ^{2} / 2^{3} * ( m^{4} n^{4} ) ^{2} * m^{4} n^{4}$=
=$2 m^{7} m^{-2} n^{-2} / m^{4} n^{4}$= $2*m/ n^{2}$